Is it possible to just replace the adjustable wood insert in threshold?

Is it possible to just replace the adjustable wood insert in threshold?
***I want to just replace the adjustable wood filler insert in the sill if at all possible.

Threshold is 36 inches as normal on the french door that opens but as you can see the entire threshold is about 75 inches long.

Screws are 10 inch apart. 3 inch in from the ends.

To put a new one in I would prob have to cut 1/2 of the 75 inch metal threshold from the door that opens at 36 inch point and put in a new one.


BUT I RATHER:
Try to determine who makes it and then if I can remove ONLY the adjustable wood sill filler since it is frozen and the screws are stripped. I would buy a new threshold and my hopes are to take it apart and just replace the adjustable sill.

Do not know who makes this. Wrote a few people with no luck.
Pictures are at my website:
Edit [Moderator]: Link removed

Thoughts?



Thank you very much, Peter